1. Field of the Invention
This invention relates to a construction system utilizing prefabricated panels adapted to form a roof, wall, flashing, accessory, tank, container, pool, pond liner, or other construction sections, and in one of its aspects to interlocking, self-cleaning fasteners for use in providing a substantially continuous seal between the panels.
2. Description of the Prior Art
The construction of roofs, walls and other elements by conventional methods is a laborious process usually requiring on-site fabrication and erection of a suitable support structure. In an attempt to improve on conventional construction methods, it has been suggested to utilize panels which are prefabricated at the factory and are secured together at the job site. Copending patent applications Ser. No. 336,370, entitled "Roof Construction," now U.S. Pat. No. 3,909,998 and Ser. No. 336,364, entitled "Construction System," both filed on Feb. 27, 1973, and assigned to the assignee of this invention, illustrate highly satisfactory apparatus and methods for providing such improvements.
In patent application Ser. No. 336,364, a composite panel is disclosed as having a structural core which may be conventional laminated foam, cellular honeycomb or concrete, as well as other construction materials. An exterior sheeting or membrane of weathertight material such as a plastic or light gauge metal is secured to the outer surface of the panel. The membrane is formed with a flap along one or several edges which is adapted to overlie a marginal portion of an adjacent panel. The membrane flap is adapted to sealingly engage the marginal portion of the next adjacent panel. In the preferred form of the invention disclosed in that application, the flap and marginal membrane portions are sealable by virtue of male and female interlocking fasteners carried on the respective membrane portions. The interlocking fastener structure may take various forms and may include an expandable section to accommodate field assembly.
In patent application Ser. No. 336,370, now U.S. Pat. No. 3,909,998, a prefabrication panel is disclosed which is ideally suited for roof construction. The panel utilizes a corrugated metal member as a structural core, and an exterior, weather resistant sheet material is pre-adhered to the panel exterior. The sheet material is formed with a flap along one or several edges which is adapted to overlie a marginal portion of an adjacent panel. A seal is effected between overlapping membrane members by vulcanization or by virtue of interlocking fasteners carried on the flap and the marginal portions of the next adjacent panel.
In any such system as described with respect to the referenced co-pending patent applications, the fasteners employed for connection to the panels in the field must be easily and quickly operated, and must provide an effective continuous seal such as against weather. However, in the fasteners employed in such systems male and female coupling members of different configurations are generally provided, and it is not uncommon for dirt to get into and along the inside of the coupling members of the fastener, particularly during field use. When such occurs, because of the relatively close fit of the coupling members of the fasteners, dirt is pushed and packed inside the fastener during joining of two fasteners until, in some cases, it is difficult to fully close the fasteners and a leak may occur between them.